The Steelers contend their lease requires the authority to pay about two-thirds of the estimated $39 million the team expects it will cost to add the end zone seats and a new video scoreboard those fans can see.

The team thought the authority could raise its share through a $1 ticket surcharge and an extra $2-$3 parking fee, but Alco Parking Co., which operates the stadium lots, has balked at that.

As a result, the authority — which runs the city’s sports stadiums and venues like its convention center — has so far refused to foot its share of the looming bill, the team says.